US4487044A - Friction compensation in a rolling mill having automatic gage control - Google Patents
Friction compensation in a rolling mill having automatic gage control Download PDFInfo
- Publication number
- US4487044A US4487044A US06/509,599 US50959983A US4487044A US 4487044 A US4487044 A US 4487044A US 50959983 A US50959983 A US 50959983A US 4487044 A US4487044 A US 4487044A
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- US
- United States
- Prior art keywords
- signal
- roll
- friction
- gap
- accordance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B37/00—Control devices or methods specially adapted for metal-rolling mills or the work produced thereby
- B21B37/16—Control of thickness, width, diameter or other transverse dimensions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21B—ROLLING OF METAL
- B21B31/00—Rolling stand structures; Mounting, adjusting, or interchanging rolls, roll mountings, or stand frames
- B21B31/16—Adjusting or positioning rolls
- B21B31/20—Adjusting or positioning rolls by moving rolls perpendicularly to roll axis
- B21B2031/206—Horizontal offset of work rolls
Definitions
- the present invention relates generally to rolling mills and more particularly to a method of compensating for friction in a metal rolling mill stand having automatic gage control to control the output gage (thickness) of a metal strip or workpiece.
- AGC BISRA gagemeter automatic gage control
- the thickness control strategy may be based upon regulation of rolling force on the assumption that constant rolling force will produce uniform output thickness.
- the amount of such hysteresis is a function of the relative centerline positions of work and backup rolls, referred to as roll "offset", the rolling force level, the forward and backward acting workpiece tensions, the backup roll bearing lubrication, the mill window and bearing chock surface condition and lubrication, and the roll balance jack seal condition. Any of these is subject to change, particularly with a change in roll chocks, making prediction of friction forces very difficult.
- the AGC system is at best inaccurate and, in the worst case, unstable.
- An example of unstable operation is that resulting from frictional forces in gagemeter systems where force sensor and actuator are on the same side of the roll bite. In this arrangement, the friction force causes the roll position to overshoot in both directions of travel. As a result, it has been the practice of many operators of such systems to detune the control to produce less than complete correction of sensed gage errors. This improves stability but decreases accuracy.
- an object of the present invention to provide a method for compensating for friction within a stand of a rolling mill.
- a rolling mill stand which includes roller elements for reducing the thickness of a workpiece passed therebetween, means for adjusting the gap between the roller elements, and additional means for sensing the roll separation force occasioned by the passing of the workpiece between the roller elements and means for sensing the roller elements' position.
- an automatic gage control means such as a BISRA gagemeter system for controlling the roll gap as a function of roll separation force.
- the force signal which is applied to the automatic gage system in accordance with the present invention is derived by sensing the apparent rolling force and compensating that sensed value for frictional forces within the rolling mill stand which occur during movement of the roller elements.
- the compensating value once derived, is combined with the apparent or sensed force signal in a first direction when the rolls are being moved in a first direction and subtracted therefrom when the rolls are being moved in a second direction.
- the invention also contemplates friction compensation as a function of the roll load; i.e., the force applied to the workpiece.
- FIG. 1 is a schematic end view of a typical mill stand useful in understanding the present invention
- FIG. 2 is a schematic view of a portion of a mill stand having certain features and effects exaggerated for purposes of illustration in the explanation of the present invention
- FIG. 3 is a graph illustrating the hysteresis effect of friction in a rolling mill stand.
- FIG. 4 is a logic diagram showing the compensation scheme of the present invention.
- FIG. 1 shows in schematic form the end view of a typical four-high mill stand.
- the stand has a housing 10 for containing the stand elements which include an upper backup roll 12 which is journaled in a suitable chock means 14.
- a lower backup roll 16 is similarly journaled in a chock 18.
- a pair of workrolls shown at 20 and 24 are journaled in respective chocks 22 and 26.
- Two pairs of balance jacks serve to support the upper chocks with respect to the mill housing.
- the first pair of balance jacks 28 and 30 is positioned between the housing and the upper backup roll chock 14.
- Workroll balance jacks 36 and 38 support the upper workroll chock 22. Similar chocks and jacks would, of course, exist on the other end of the stand.
- a suitable screw mechanism 44 acting through a nut 46 serves to provide rough dimensioning of the space (gap) between the two workrolls 20 and 24 through which a workpiece 60 is passed.
- a hydraulic system illustrated at 48 which is essentially a piston within a cylinder, (herein referred to as the "cylinder") which will, as is known in the art, serve to provide adjustment in accordance with the automatic gage control (AGC) system. It is also known that the cylinder can be omitted and have the AGC work directly through the screw 44.
- the screw 44 and cylinder 48 act upon the backup roll chock 14 by way of a load cell 50.
- the load cell provides an output force signal (signal on F s line 56), which is proportional to the rolling force resulting from the workpiece 60 being passed between the workrolls 20 and 24 as modified by the friction forces here being discussed.
- F s line 56 an output force signal
- FIG. 50' Showted in phantom form at the bottom of the stand between the lower backup roll chock 18 and the housing is a load cell 50'. This is meant to show an alternate location of the load cell which is sometimes employed.
- Sensing means 51 provides the output signal (S o ) on line 52 which is indicative of the position of the piston within the cylinder and hence an indication of the roll gap.
- Sensor 53 is a pressure sensor which senses the internal pressure within the cylinder and provides a pressure signal (F s ') on output line 54 which may also be utilized as an indication of the rolling force.
- Hydraulic fluid is supplied to the cylinder 48 by way of a suitable pump under the control of the AGC system and by way of a suitable connection shown at 58 as will be more fully explained with respect to FIG. 4.
- FIG. 1 A final feature to be mentioned with respect to FIG. 1 is that, as indicated, the centers of the workrolls are offset from the centers of the backup rolls by some small amount, for example one-quarter inch, to lend stability to the overall mill system.
- the overall depiction of FIG. 1 is one which is very common in the art and well understood by those versed therein.
- the frictional forces with which the present invention is concerned originate primarily in two general areas.
- the first of these areas is in hydraulic systems; i.e., the cylinder 48 and the balance jacks which support the backup and workroll chocks.
- These jacks are normally hydraulic jacks, and like system 48 have a piston working through a seal.
- the friction between the piston and the seal can be quite severe.
- the friction of the roll chocks as they are moved and slide along the interior sides (the window) of the mill housing.
- FIG. 2 illustrates a portion of the elements of FIG. 1 and has certain features exaggerated for purposes of illustration.
- the roll chocks tend to disalign or skew themselves with respect to the mill housing such that point contacts A through H tend to develop between these chocks and the housing. From this illustration, it is seen that with any movement of the chocks against the housing, such as when the roll position is varied for gage control purposes, friction forces will be developed which will be sensed by the force sensors; e.g., the load cell 50 (or 50') or the pressure sensor 53 (FIG. 1).
- the signal from the sensor is that used in the AGC system as is well known.
- the frictional forces act with respect to the overall sensed force in different directions according to the location of the force sensing means and the direction of chock or roll travel.
- the friction forces due to the chocks contact with the mill housing, those associated with the balance jacks and those associated with the cylinder will all add to the actual roll separation force as seen by the force sensor when the mill roll gap is being closed and will subtract from the actual force when the gap is being increased.
- load cell 50' when the sensor is on the opposite side of the roll gap from the gap adjusting such as indicated by FIG. 1, load cell 50', only the frictional forces associated with the bottom roll chocks need to be considered and these will subtract from the actual force when the mill is closing and will add to the actual force when the mill is opening.
- F S total force sensed by sensor 50 (or sensor 53)
- f brb frictional force of backup roll balance jacks
- FIG. 3 illustrates the hysteresis effect which was earlier mentioned and which is exemplified by the equation pairs above.
- FIG. 3 plots the sensed rolling force against the changing roll gap from an actual mill test and it is seen that, as is apparent from the two equations, the rolling force differs in opening and closing.
- N d number of scans in closing direction
- N w number of scans in opening direction
- V T gap change velocity threshold
- f 1 will be in units of force.
- One means of developing such a per unit value is to develop an average force value (F avg ) and to derive from that a per unit force value (f) in accordance with the following relationships: ##EQU2##
- FIG. 4 One method by which this may be achieved is illustrated in FIG. 4.
- the signs in FIG. 4 represent the situation where the force sensing means and the roll gap adjusting means are on the same side of the roll gap. It should be noted that in the situation of a force sensor located on an opposite side of the gap from the roll gap adjusting means, such as illustrated by the load cell 50' in FIG. 1, mathematical relationship of blocks 114 and 116 would be interchanged.
- a signal S o the position signal from the sensor 51 of cylinder 48 in FIG. 1, is applied to a differentiating block 100 which provides as its output a signal which is indicative of the roll changing velocity and has a polarity, plus or minus, in accordance with the direction in which the roll gap is changing.
- This signal designated ( ⁇ )v is applied to two logic blocks 102 and 104 which determine, respectively, whether the velocity signal v is less than minus some terminal velocity V T (block 102) or greater than the positive value of V T (block 104). If the logic decision of both blocks 102 and 104 is "No" the force sensed is the force actually used and this signal is then applied, as indicated by block 106, to an AGC system 108.
- the AGC system applies a signal to a pump control 110 to control a pump 112 which supplies pressure to the cylinder 48 (FIG. 1) by means of line 58.
- signal v Assuming that the output of block 100, signal v, has a negative value less than -V T (roll gap is decreasing) then, as shown by block 114, that the actual force signal F to be supplied to the AGC is equal to the sensed force (F s ) times the quantity of 1-f.
- the other condition for this particular set of circumstances is that the velocity signal v is greater than +V T (roll gap is increasing).
- the force signal to be supplied by the AGC system is equal to the actual sensed force times the quantity (1+f). Since f is a per unit quantity, the variation in friction force with rolling force level is automatically accomodated by this method.
- a modified embodiment would permit the friction signal, f, to decay exponentially from the level existing when the velocity signal v falls beneath the threshhold VT in either direction. This more closely approximates the actual decay of friction in the mill elements.
- the decay time constant can be estimated from simple field tests and is typically of the order of 0.3 to 1.0 seconds.
- One method of achieving this modified embodiment is to use a per unit friction signal which is defined by the relationships:
- V T gap change velocity threshhold
- FIG. 4 is a logical description of the operations to be performed in accordance with the present invention. It is readily apparent to those skilled in the art that these functions could be performed either by analog circuitry or by data processing equipment with comparable results. It is believed, however, that in today's state of the art, the data processing or digital system would be preferable in which case it is apparent that the two signal S o and F s as well as the friction signals f would have to be digitalized.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Control Of Metal Rolling (AREA)
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/509,599 US4487044A (en) | 1983-06-30 | 1983-06-30 | Friction compensation in a rolling mill having automatic gage control |
GB08411222A GB2142264B (en) | 1983-06-30 | 1984-05-02 | Friction compensation in a rolling mill having automatic gauge control |
SE8402849A SE8402849L (sv) | 1983-06-30 | 1984-05-25 | Sett att kompensera friktionen hos en valsstol med automatisk konstanthallning av valsgodsets tjocklek |
FR8409643A FR2548058A1 (fr) | 1983-06-30 | 1984-06-20 | Procede de compensation du frottement dans un laminoir muni d'une commande automatique du calibre |
DE19843422762 DE3422762A1 (de) | 1983-06-30 | 1984-06-20 | Verfahren zur reibungskompensation in einem walzwerk |
JP59133400A JPS6049809A (ja) | 1983-06-30 | 1984-06-29 | 圧延スタンドの摩擦の力を補償する方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US06/509,599 US4487044A (en) | 1983-06-30 | 1983-06-30 | Friction compensation in a rolling mill having automatic gage control |
Publications (1)
Publication Number | Publication Date |
---|---|
US4487044A true US4487044A (en) | 1984-12-11 |
Family
ID=24027340
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US06/509,599 Expired - Fee Related US4487044A (en) | 1983-06-30 | 1983-06-30 | Friction compensation in a rolling mill having automatic gage control |
Country Status (6)
Country | Link |
---|---|
US (1) | US4487044A (ja) |
JP (1) | JPS6049809A (ja) |
DE (1) | DE3422762A1 (ja) |
FR (1) | FR2548058A1 (ja) |
GB (1) | GB2142264B (ja) |
SE (1) | SE8402849L (ja) |
Cited By (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4700610A (en) * | 1984-09-17 | 1987-10-20 | Hoerbiger Ventilwerke Aktiengesellschaft | Cylinder tube strain measurement feedback for piston position control |
US4805429A (en) * | 1987-12-28 | 1989-02-21 | General Electric Company | Shot peening system and method with velocity sensing |
US5048316A (en) * | 1991-01-28 | 1991-09-17 | General Electric Company | Pressure pot shot peening system having a holder |
US5383610A (en) * | 1992-06-17 | 1995-01-24 | Krupp Polysius Ag | Method of operating a material bed roll mill |
US6041632A (en) * | 1997-09-10 | 2000-03-28 | Kawasaki Steel Corporation | Pipe forming roll apparatus and method |
US6116073A (en) * | 1995-12-21 | 2000-09-12 | Hitachi, Ltd. | Cluster type multi-roll rolling mill and rolling method |
US20040045332A1 (en) * | 2002-03-26 | 2004-03-11 | Takeshi Sakai | Load measuring system for a thread rolling machine and operating method therefor |
US20070245794A1 (en) * | 2005-06-08 | 2007-10-25 | Peter Brandenfels | Device for Loading the Guide Surfaces of Bearing Chocks Supported in the Housing Windows of Rolling Stands |
CN107159799A (zh) * | 2017-07-11 | 2017-09-15 | 湖南坚致幕墙安装设计有限公司 | 板材冷弯成型模具 |
US11203049B2 (en) | 2017-09-19 | 2021-12-21 | Alunetic Aps | Apparatus for flatting, punching or stamping |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS63168210A (ja) * | 1986-12-27 | 1988-07-12 | Nippon Steel Corp | 板圧延における板幅制御方法 |
JP7365634B2 (ja) | 2019-10-17 | 2023-10-20 | パナソニックIpマネジメント株式会社 | 熱交換器 |
JP7365635B2 (ja) | 2019-10-17 | 2023-10-20 | パナソニックIpマネジメント株式会社 | 熱交換器 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3081652A (en) * | 1955-11-30 | 1963-03-19 | Westinghouse Electric Corp | Taper rolling mill control |
US3613419A (en) * | 1969-08-01 | 1971-10-19 | Westinghouse Electric Corp | Rolling mill automatic gauge control with compensation for transport time |
US3704609A (en) * | 1971-06-25 | 1972-12-05 | Westinghouse Electric Corp | Rolling mill gauge control during acceleration |
US3787667A (en) * | 1971-01-06 | 1974-01-22 | Gen Electric | Computer controlled metal rolling mill |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5326229B2 (ja) * | 1974-03-08 | 1978-08-01 |
-
1983
- 1983-06-30 US US06/509,599 patent/US4487044A/en not_active Expired - Fee Related
-
1984
- 1984-05-02 GB GB08411222A patent/GB2142264B/en not_active Expired
- 1984-05-25 SE SE8402849A patent/SE8402849L/ not_active Application Discontinuation
- 1984-06-20 FR FR8409643A patent/FR2548058A1/fr not_active Withdrawn
- 1984-06-20 DE DE19843422762 patent/DE3422762A1/de active Granted
- 1984-06-29 JP JP59133400A patent/JPS6049809A/ja active Granted
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3081652A (en) * | 1955-11-30 | 1963-03-19 | Westinghouse Electric Corp | Taper rolling mill control |
US3613419A (en) * | 1969-08-01 | 1971-10-19 | Westinghouse Electric Corp | Rolling mill automatic gauge control with compensation for transport time |
US3787667A (en) * | 1971-01-06 | 1974-01-22 | Gen Electric | Computer controlled metal rolling mill |
US3704609A (en) * | 1971-06-25 | 1972-12-05 | Westinghouse Electric Corp | Rolling mill gauge control during acceleration |
Non-Patent Citations (4)
Title |
---|
"Force Sensing in Rolling Mills", by A. Zeltkalns et al., Iron and Steel Engineer Yearbook, 1977--pp. 40-46. |
"Mill Modulus Variation and Hysteresis--Their Effect on Hot Strip Mill AGC", by G. E. Wood et al., Iron and Steel Engineer Yearbook, 1977--pp. 33-39. |
Force Sensing in Rolling Mills , by A. Zeltkalns et al., Iron and Steel Engineer Yearbook, 1977 pp. 40 46. * |
Mill Modulus Variation and Hysteresis Their Effect on Hot Strip Mill AGC , by G. E. Wood et al., Iron and Steel Engineer Yearbook, 1977 pp. 33 39. * |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4700610A (en) * | 1984-09-17 | 1987-10-20 | Hoerbiger Ventilwerke Aktiengesellschaft | Cylinder tube strain measurement feedback for piston position control |
US4805429A (en) * | 1987-12-28 | 1989-02-21 | General Electric Company | Shot peening system and method with velocity sensing |
US5048316A (en) * | 1991-01-28 | 1991-09-17 | General Electric Company | Pressure pot shot peening system having a holder |
US5383610A (en) * | 1992-06-17 | 1995-01-24 | Krupp Polysius Ag | Method of operating a material bed roll mill |
US6116073A (en) * | 1995-12-21 | 2000-09-12 | Hitachi, Ltd. | Cluster type multi-roll rolling mill and rolling method |
US6216940B1 (en) | 1997-09-10 | 2001-04-17 | Kawasaki Steel Corporation | Pipe forming roll apparatus and method |
US6041632A (en) * | 1997-09-10 | 2000-03-28 | Kawasaki Steel Corporation | Pipe forming roll apparatus and method |
CN1090065C (zh) * | 1997-09-10 | 2002-09-04 | 川崎制铁株式会社 | 使用轧辊的成形用机架和成形方法 |
US20040045332A1 (en) * | 2002-03-26 | 2004-03-11 | Takeshi Sakai | Load measuring system for a thread rolling machine and operating method therefor |
US6912883B2 (en) | 2002-03-26 | 2005-07-05 | Minebea Co., Ltd. | Load measuring system for a thread rolling machine and operating method therefor |
US20070245794A1 (en) * | 2005-06-08 | 2007-10-25 | Peter Brandenfels | Device for Loading the Guide Surfaces of Bearing Chocks Supported in the Housing Windows of Rolling Stands |
US7426844B2 (en) * | 2005-06-08 | 2008-09-23 | Sms Demag Ag | Device for loading the guide surfaces of bearing chocks supported in the housing windows of rolling stands |
CN107159799A (zh) * | 2017-07-11 | 2017-09-15 | 湖南坚致幕墙安装设计有限公司 | 板材冷弯成型模具 |
US11203049B2 (en) | 2017-09-19 | 2021-12-21 | Alunetic Aps | Apparatus for flatting, punching or stamping |
Also Published As
Publication number | Publication date |
---|---|
GB2142264B (en) | 1987-04-01 |
FR2548058A1 (fr) | 1985-01-04 |
JPS6049809A (ja) | 1985-03-19 |
JPH024367B2 (ja) | 1990-01-29 |
SE8402849L (sv) | 1984-12-31 |
DE3422762A1 (de) | 1985-01-03 |
SE8402849D0 (sv) | 1984-05-25 |
GB8411222D0 (en) | 1984-06-06 |
DE3422762C2 (ja) | 1990-07-05 |
GB2142264A (en) | 1985-01-16 |
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